Blue Whales in San Diego

Balaenoptera musculus

Blue whales are a migratory species and the largest of all the whale species. We typically see Blue whales on our San Diego dolphin and whale watching tours starting in June through the early fall. Blue whales are often encountered farther offshore which means having a faster boat with an expanded search range equates to a greater chance of sightings. Blue whales arrive with the large congregations of krill (a pelagic crustacean) and their preferred food source. So we often observe Blue whales feeding in the offshore San Diego marine environment. For the best chance of seeing Blue whales in San Diego we recommend following our tour sightings reports that we share on our Facebook and Instagram pages.

Blue Whale Info

Description – Blue whales are the largest whales in the world, in the northern hemisphere reaching up to 90 feet and 230,000 pounds. They are named for the bluish color of their skin when reflecting light underwater. The largest of the rorquals, the Blue whale has baleen plates, up to 80 pleated throat grooves, small pectoral fins and a tail fin up to 15 feet wide. They have 2 blow holes behind the elevated ridge on their cranium and their exhalations can reach over 30 feet high.

Range – Blue whales can be found throughout all the worlds oceans. Research into their migration is still trying to understand their movements, but there is a general understanding that most Blue whales follow seasonal migration between polar regions in summers and subtropical areas in winters. For example the Blue whales seen off San Diego over the summer and fall have been tracked into the Sea of Cortez and off of Costa Rica during the winter months.

Behavior – Blue whales are solitary filter feeders swimming at approximately 5mph while traveling, although they can reach 20mph when feeding. To feed they lunge into dense concentrations of krill with their mouths agape. Their enormous throat expands to encompass the krill and a large quantity of water. Then the tongue pushes the water out of their mouth through the baleen which strains out the krill before swallowing. They can consume over 6 tons of food in a day, although scientists are now evaluating data that shows they could actually be eating twice that!

When we see Blue whales in San Diego they are often traveling between feeding areas. Their surface behavior is usually 3-4 breath cycles and if we are lucky, the enormous tail rises up as they dive. Sometimes we see 2 whales traveling together, normally this is a mother and calf pair.


The Blue whale population along the west coast of North America is estimated to be approximately 1,500 whales, globally at 10,000-25,000. The California group of Blue whales is still struggling to rebound from the affects of whaling pressure and is listed under the Endangered Species Act. One of the ways Oceanic Eco Tours endeavors to assist in the research and conservation of Blue whales is to report our Blue whale sightings and submit our identifying images to help assess the population.

The primary threats to the California Blue whale population includes; ship strikes, entanglement in fishing gear and noise pollution. At Oceanic Eco Tours we endeavor to mitigate these threats by; operating a smaller boat, following responsible boating practices in the presence of cetaceans, collecting abandoned fishing gear and using the latest engine technology to limit noise pollution in the Blue whales environment.